The present invention relates to a method for generating electric signals and a novel push-button switching means therefor.
Many electric or electronic instruments and appliances are provided with one or more push-button switches which generate electric signals by the contacting and coming apart of the contacting terminals in the switching device. For example, an electronic pocket calculator has a key-board switch panel in which several push-button switches are arranged corresponding to the numerical figures and mathematical operators used in calculation. These push-button switches are pushed, usually, with a finger tip to operate the electronic circuit built into the calculator.
One of the important and unavoidable problems in the switching means of such a type is chattering or bouncing which may lead to erroneous operation of the electronic circuit. Accordingly, there have been made various attempts to obtain a push-button switch with little or no chattering or bouncing. An approach in obtaining such an improved switch means is the use of an electroconductive rubbery elastomer as the material for the contacting points in the switch.
Although chattering or bouncing of the switch can be greatly reduced by the use of such an electroconductive rubbery elastomer, when compared with a switching device having metallic contacting points, no satisfactory results have been obtained hitherto.